1. Field of the Invention
The present invention relates to a light emitting diode (LED) lamp, and more particularly, to an LED lamp in which an LED can be easily exchanged and external vibration can be absorbed to prevent excess free play therein.
2. Discussion of the Background
Generally, an LED is an electronic device that emits light through recombination of injected minority carriers (electrons or holes) using a p-n junction of a semiconductor. That is, when electric power is applied to a semiconductor of a specific element in a forward direction, electrons and holes move through the junction of positive and negative electrodes, and are recombined with each other and then have energy lower than those of separate electrons and holes. The difference in energy generated at this time causes light to be emitted.
Such an LED has a smaller size and a longer life span and can emit light with high efficiency using a lower voltage as compared with conventional light sources. In particular, since LEDs have a rapid response property, they are widely used for indicator lamps or digit indicators of various electronic equipment, such as indicators of instrument panels of automobiles or light sources for fiber optic communication, and are also applied in different ways, such as lighting means for houses, vehicles, ships, traffic signals, a variety of guide lights, exit sign lights, and the like.
FIG. 1 is a perspective view showing a printed circuit board (PCB) to which LED chips are mounted using surface mount technology, and FIG. 2 is a perspective view showing a PCB to which LED packages are mounted by means of clinching.
Since a single LED chip or package cannot give sufficient illuminance and luminance, an LED lamp includes about 20 or more LED chips or packages (the number thereof varies depending on use of the lamp) that are arranged in parallel or in series to form a circuit.
Among LED lamps, the LED lamp of FIG. 1 is manufactured using surface mount technology (SMT) in such a manner that LED chips are mounted directly on a PCB and then fixed thereto by means of soldering.
However, in the LED lamp manufactured using SMT as described above, there is inconvenience in that if an LED chip is out of order, solder used for fixing the LED chip should be removed and then a new LED chip should be soldered again upon mounting thereof. In addition, if external vibration is applied thereto, there is a high possibility that a copper plate of the PCB will be separated due to the vibration.
Meanwhile, the LED lamp of FIG. 2, which is made by means of clinching, does not require additional soldering since lead frames of the LED package are attached to the PCB by means of clinching.
However, since the LED lamp made by means of clinching has a plurality of LED packages connected in series, the LED lamp has a disadvantage in that the entire module should be replaced even though only one LED package is out of order. In addition, since the LED packages are attached through clinching, there is a high possibility that a circuit on the PCB will be short-circuited.